Micrometer-calipers



(No Model.)

J. BYSTROM.

MIUROMETER GALIPERS.

l 8 Q I fina/afar' NTTED STATES PATENT Orrrcn.

JOHN BYSTROM, OF CHICAGO, ILLINOIS.

lvllcRoMETr-:R-CALIPERS.

SPECIFICATIONformng part of Letters Patent N o. 542,676, dated July 16, 1895. Application iiled November 22, 1894:. Serial No. 5291574- (NO model.)

To allgwhom t may concern: g

Be it known that I, JOHN BYs'rRoM, a citizen of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented a certain new and useful Improvement in Calipers and Micrometers; and I declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same, vreference being had to the accompanying drawings, which form a part of this specification, in whichi Figure l is a side view of my improved calipers designed for use as both inside and outside calipers, and where very fine adjustment is required. Fig. 2 is an edge view of the same. Fig. 3 is a side view, partly in section, showing the construction and jaws of the calipers partly extended. Fig. 4t is an enlarged View of one of the lower jaws, it being the end on which is the adjusting-block. Fig. 5 is a view on line 5 of Fig. 4E. Fig. 6 is a view showing the construction when used as a micrometer. Fig. 7 is an enlarged section on line 7 of Fig. 6, showing the mode of attach- .ment of the scale-bars to the thumb-nut.

Fig. 8 is a section on line -8 of Fig. 6, viewed in the direction of the arrow.

Myinvention has for its object the production of an instrument usually known as calipers or micrometers, which, besides having the usual adaptabilities of such instruments, will also be adapted to both inside and outside measuring, and, further, to give both the inside and outside measurement with only one setting, and, lastly, when used for the purpose of sizing a hole or opening through which a shaft or other body is to pass or t into, it may, by means of an adjustable scaled block, be so set that it will give, by simply taking the measurement of the shaft or like body which is to pass through or tit into the hole or' opening and preadjusting the said block, the exact size of such hole or opening and, first, leave allowance for shrinkage; second, a tight or driving flt;third, the exact outside diameter of the body measured, and, fourth, a loose fit; and to this end the nature of the invention consists of providing a scalebar, to one end of which is rigidly secured one jaw of the calipers, and having loosely mounted thereon the other jaw, having a setscrew so as to lock it in any desired position. Attached -to this jaw, by means of a screw having a thumb-nut thereon and also sliding upon the scale-bar, is a block alsohaving a set-screw to lock it in position, by means of which a very tine adjustment of the movable jaw of the calipers may be had. To the end ot one of thejaws used for inside measuring is attached the adjustable block used forthe diiferentset measurements referred to above, also having its proper adjusting and set screws. When these jaws are applied tothe micrometer there are two scale-bars, one on either side of the jaws and rigidly secured to the outer jaw, while to the inner jaw is secured the threaded adjusting-spindle.

` The invention further consists in a combination of devices heroinafterdescribed, and

` upon this bar is the movable jaw A2 having the set-screw ct to lock it in any desired position. These jaws A and A2 are preferably made so that theinner side ofthe upper portions A8 and A4 lie a little outside the verti- -cal plane of the outer sides of the lowerportions A5 and A6.

Attached to the jaw A2 by means of a screwthreaded bar h is a movable block C, which is also mounted loosely upon the bar B and having the setscrew c to lock it in position. This block is preferably mountedloosely upon the threaded bar h, is cut away, as at c', to admit of the insertion of au internally-threaded thumbnut b', traveling upon the threaded bar b. By meansof this thumb-nut band threaded bar b the jaw A2 can be, very minutely adjusted.

TWhen it is desired to take a measurement, the set-screws a and c of the jaw A2 and block C, respectively, are loosened and the said jaw IOO and block moved along the scale-bar to approximately fit the article which it is desired to measure. The set-screw c is tightened, securely holding the block C in place. The jaw A2 is then adjusted to the exact position required by means of a thumb-nut b and threaded bar b.

Near the end of one of the lower jaws, or

riveted or otherwise secured in its place'so` as to cover the way at the inner end. Through this cap-piece D3 passes ari-adj us-ting-screw d', which Works ina tap in the inner end of the movable block D and may have a ,collar yCZ or other means to prevent it from withdrawing but allow it to revolve freely, and when so turned will move the block D in or out; and immediately below the path of the said block is a small set-screw d2 to firmly hold it in any position desired. The opposite jaw of the calipers is cut out, as at fr, to tit over the head of the screw al so as to allow the jaws to come close together. This block D' has marked upon the face, which is exposed through the opening s, four marks to indicate, first, the size to make the opening, with allowance for shrinkage; second, what is called a driving or tight tit; third, the exact outside diameter of the piece measured, and,

fourth, what is called a loose fit, and four corresponding marks or pointers are marked upon the side'of t-he jaw. It is desirable to have the pointers upon the jaw slightly farther apart than those on the block,so that if, for insta-nce, the second mark or graduation is required, only the second mark on the block and the second pointer on the jaw will coincid e, thus making the exact position more discernible. This, however, is not essential to the spirit of my invention. The purpose of these graduations is this, taking, for example, that it is desired to fit a collar on a shaft and have it a tight or driving fit: Before measuring the shaft the block D is moved out 'by means of the adjusting-screw d, so that the second mark, or the one corresponding to driving fit, on the block and the second pointer on the jaw coincide. By means of the screw d the block is thenlocked in this position. The shaft is then calipered, as above described, and there is given on the jaws designed for inside measurement the exact size that it is required to make the opening in the collar in order to ha-ve a driving fit. V any of the other sizes above referred to are reqnired, moving the block to correspond with the one desired.-

This same process is had whenv This instrument can of course be used as ordinaryinside and outside calipers. The bar B being graduated in inches and fractions thereof will always give the correct measurement in inches or fractions thereof.

' In Fig. 6 is shown a micrometer embodying my improvements, with these differences, however, that in this there are two parallel bars E and E', which are rigidly secured tothe outer jaw F at one end, while the other ends terminate in a collar e, Which surrounds the end of the handle G, which also serves as a thumb-nut to open and close the jaws, which turned down will form a shoulder, so that the collar will make a flush t. This handle is internally threaded at the inner end to accommodate the nut G,which is drilled through the center 'to-allow the' passage of the spindle I-I. This nut G has ashouldjer on its outer end slightly larger than the turned-down portion of thev handle and when in place confines the coll-ar e ofthe bars F. and E into its proper place, thu-s preventing the handle or thumbnut G from pulling out, but at the same time allowingr it to revolve freely. The spindle Il is thread-ed at one end to f1ta corresponding thread or tap in the thumb-nut G and at the other end is rigidly secured to the movable jaw F', which moves between the two bars E and E" Upon the collar e is amark or station oint e While the thumb-screw may, for

example, have twenty-tive points in its circumference,and if the thread on the spindle be forty threads to the inch by turning the nut G one point the jaws are moved one way or the other one one-thousandth of one inch,

'or one of the bars E or E may be marked forty movement of one one-thousandth of an inch more perceptible. The other edge of the bars may be marked in regular fractions of an inch-as sixteenths, thirty-seconds, &c.-the

exact marking being immaterial to the spirit and a graduated pin K is inserted for the purpose of taking very small diameters, there being a small thumb-screw passing through the jawat right angles to the split above referred to for the purpose of locking the pin K at any desired position.

/Vhile I have yherein shown and described details of my invention, I do not, however, wish to limit myself to this exact construction, as the parts may obviously be changed and reversed without departing-from the spirit of my invention.

IIa-ving thus described my invention, what I claim is- The combination with a caliper, micrometer or similar linstrument adapted for both in l and outside measuring of an adjustable block,

set in one of said jaws, having on its face four IIOl marks or graduatons, corresponding marks taken by said opposite jaws, or for .a iight fit, g or graduations on the jaw wherein said block substantially as and for the purposes set forth. :o

is ser, said graduationson saidblock repre- In testimony whereofl I have signed this senting and, when setfon eitherone, adapted specification in the presence of tWo witnesses. 5 to give, When a measurement is taken by the JOHN BYSTROM.

opposite j ldws, the size required leaving allow- Witnesses:

ance for shrinkage of the material operating ALF ROESSNER,

upon, for a loose t, the exact measurement OTTO SCHRAM. 

